Superconducting thermal neutron detectors

6th European Conference on Neutron Scattering

Merlo, V.^1 ; Pietropaolo, A.^2,3 ; Celentano, G.^2 ; Cirillo, M.^1 ; Lucci, M.^1 ; Ottaviani, I.^1 ; Salvato, M.^1 ; Scherillo, A.^1 ; Schooneveld, E.M.^4 ; Vannozzi, A.^2

Universita Degli Studi di Roma Tor Vergata, Physics Department and MINAS Lab, via della Ricerca Scientifica 1, Roma

00133, Italy^1

ENEA, Fusion and Nuclear Safety Technologies Dept., Via E. Fermi 45, Frascati (Roma)

00044, Italy^2

MIFP-Mediterranean Institute of Fundamental Physics, Via Appia Nuova 31, Marino (Rome)

00040, Italy^3

Science and Technology Facility Council, ISIS Facility Chilton, Oxfordshire, Didcot

OX11 0QX, United Kingdom^4

关键词: Neutron detection;    Niobium nitride;    Physical features;    Pulsed neutron beams;    Secondary particles;    Spallation neutron sources;    Superconducting strips;    Thermal neutron detectors;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/746/1/012019/pdf
DOI  :  10.1088/1742-6596/746/1/012019

来源: IOP

【 摘 要 】

A neutron detection concept is presented that is based on superconductive niobium nitride (NbN) strips coated by a boron (B) layer. The working principle is well described by a hot spot mechanism: upon the occurrence of the nuclear reactions n +10B → α +7Li + 2.8 MeV, the energy released by the secondary particles into the strip induces a superconducting-normal state transition. The latter is recognized as a voltage signal which is the evidence of the incident neutron. The above described detection principle has been experimentally assessed and verified by irradiating the samples with a pulsed neutron beam at the ISIS spallation neutron source (UK). It is found that the boron coated superconducting strips, kept at a temperature T below 11K and current-biased below the critical current IC, are driven into the normal state upon thermal neutron irradiation. Measurements on the counting rate of the device are presented and the basic physical features of the detector are discussed and compared to those of a borated Nb superconducting strip.